1. Field of the Invention
The present invention relates to the use of a dihydrochalcone-rich phenolic fraction in the cosmetic treatment of mammals in order to limit the weight, to improve the aesthetic appearance of the body and to treat certain non-pathological forms of obesity. The invention also relates to the use of a dietary or nutraceutical composition based on this phenolic fraction. The present invention also discloses a composition based on this phenolic fraction for its use as a medicinal product intended to be used in the prevention of diabetes.
2. Description of the Related Art
It is known that polyphenolic compounds are very widespread in the plant kingdom. The most abundant are chlorogenc acid, procyanidins B1 and B2, epicatechin, phloretin, phloridzin. and p-coumaric acid. Consequently, many polyphenol-rich products are available on the market, the most common being extracted from green tea, from grapeseeds and from pine bark (U.S. Pat. No. 4,698,360, EP A 348 781, EP A 283 349, FR A 1 427 100, FR A 2 092 743, FR A 2 643 073 and FR A 2 372 823).
Patent EP A 0 657 169 has already disclosed the extraction of a polyphenolic fraction from unripe fruit (weighing from 3 to 10 grams) of the Rosacea family (apple, pear, etc.). The polyphenolic fraction thus defined is characterized by a high content of derivatives of the hydroxycinnamic acid family (chlorogenic acid, caffeic acid and p-coumaric acid) and of molecules from the flavanol family (catechin, epicatechin and procyanidin). The phloridzin of these extracts derived from unripe fruit represents less than 7% by weight off all of the phenolic compounds, and the typical dihydrochalcones (phloridzin and phloretin) of Rosacea plants less than 9%. Among the phenolic compounds present in the plant kingdom, phloretin and its glycosylated derivative, phloridzin, are typical of apple and of other fruits of the Rosacea family. Phloridzin is found in large amounts in the pips and bark of trees, and in much lower amounts in apple juice and peel. and in much lower amounts in apple juice and peel.
Phloridzin has been known for a long time for its activity in blocking the assimilation of glucose. One of the mechanisms of action. described is considered to be that phloridzin comes into competition with simple sugars and, consequently, limits their transport in the blood (Alvarado and Crane, Biochim. Biophys. Acta, 56, pp. 170, 1962). Another mechanism, possibly linked to the previous one, is considered to involve the blocking of the sodium-dependent transport systems of sugars such as glucose, galactose, xylose, etc., in the small intestine (Esaki et al., Agric. Biol. Chem., 55, 11, pp. 2855, 1991). It appears that the ‘natural’ transporter of sugar has two independent sites, the site with ‘sugar’ affinity and the site with ‘phenol’ affinity, and that, by binding strongly to the transporter by interaction with the two sites, phloridzin blocks the transport of sugars across the membranes.
These hypotheses were confirmed by in vivo studies. Phloridzin has been successfully studied experimentally for a long time for reducing the availability of blood glucose and inducing glycosuria (presence of glucose in the urine) in sheep (Goetsch and Pritchard, Am. J. Vet. Res., 19, pp. 637, 1958), goats (Schultz et al., J. Dairy Sci., 32, pp. 817, 1949) and cattle (Lyle et al., J. Dairy Sci., 67, pp. 2255, 1984; Young et al., J. Dairy Sci., 57, pp. 689, 1974). 2 to 4 grams of phloridzin per day for 48 h as a subcutaneous injection in a cow are sufficient to bring about a drastic reduction in the glucose and insulin contents of the blood plasma and the excretion of 225 to 337 grams of glucose per day in the urine of the treated animal (Amaral-Phillips et al., J. Dairy Sd., 76, pp. 752, 1993).
This mechanism of blocking the membrane transport of glucose is very advantageous in particular in Western diets for preventing diabetes and for treating certain forms of obesity. Thus, two patents involve phloridzin in medicinal compositions intended to block glucose transport. Patent CZ 1993000931986 (Valovic) discloses a mixture based on phosphoric acid, sulphuric acid, lactic acid, creosote, arsenic trioxide, sodium sulphate and plant extracts including phloridzin extracted from fruit tree bark. Patent U.S. Pat. No. 5,985,850 (Falk and Asculai) discloses pharmaceutical compositions involving hyaluronic acid as transporter of active molecules (including phloridzin or molecules of the same family) for blocking glucose transport in certain types of cells.
In apple homogenate or apple juice, the dihydrochalcones (phloretin and phloridzin) are present in a minor amount compared with the other polyphenols. Chlorogenic acid and procyanidins are the major polyphenols of apples, whether these are cider apples or dessert apples, phloridzin and phloretin never representing more than 5% by weight o f the total polyphenols of ripe apples (Karadeniz and Ekski, Scientific Technical Com. Int. Fed. Fruit Juice Producers, 24, pp. 265-275, 1996; Sanoner et al., Polyphenolic profiles of French cider apple varieties. In ‘Polyphenols, wines and health’, Symposium, Bordeaux, 14-16 April, 1999; Sanoner et al., J. Agric. Food Chem., 47, pp. 4847-4853, 1999).
In the known polyphenolic extracts, the proportions between the various phenolic molecules are retained relative to the proportions present in the various starting materials. Polyphenolic extracts rich in hydroxycinnamic acids (caffeic acid, chlorogenic acid and p-coumaric acid) and poor in dihydrochalcones (phloridzin and phloretin) are thus conventionally obtained:
Apple*Known polyphenolic(in mg/L of juice orextract of applePhenolic compoundmg/kg of homogenate(in mg/kg of powder)Ceffeic acidε 21.7Catechinε to 150 15.1Chlorogenic acid60 to 1200161.0Procyanidins500 to 5,000 69.6 (B1 and B2)p-Coumaric acid1 to 150 9.3Epicatechinε to 1,400 41.4Phloridzin6 to 100 32.7Quercitrinε 1.9Phloretin5 to 100 9.5Total polyphenols483.4(expressed as phloridzinequivalent)ε = unquantifiably low amount*values compiled from measurements on 15 varieties of cider apples and 3 varieties of dessert apples over 3 harvests (Karadeniz and Ekski).
Caffeic acid is in fact a decomposition product of chlorogenic acid, since there is only very little caffeic acid, indeed even none at all, naturally present in apples (Fiedler, Arzneimittel-Forsch, 4, pp. 41, 1954).
The disclosures of the documents listed in this section and elsewhere throughout this application are incorporated herein by reference.